<template>
  <el-tooltip class="box-item" effect="dark" :content="titles.join(' / ')" placement="bottom" :offset="0"
    :show-arrow="false">
    <el-breadcrumb class="app-breadcrumb" separator="/">
      <template v-for="(item, index) in  levelList.slice(0, 3)">
        <el-breadcrumb-item v-if="getTitle(item.meta.title, index)" :key="item.path">
          <span v-if="item.redirect === 'noRedirect' || index == levelList.length - 1" class="no-redirect">{{
            getTitle(item.meta.title, index)
          }}</span>
          <a v-else @click.prevent="handleLink(item)">{{ getTitle(item.meta.title, index) }}</a>
        </el-breadcrumb-item>
      </template>
    </el-breadcrumb>
  </el-tooltip>
</template>

<script setup>
const route = useRoute();
const router = useRouter();
const levelList = ref([])


const titles = computed(() => levelList.value.map(d => d.meta.title))
const getTitle = (d, i) => {
  let len = 0
  for (let index = 0; index <= i; index++) {
    const item = titles.value[index]
    len += item.length
    if (len > 8) {
      return i > index ? '' : item.slice(0, 8 - len) + '...'
    }
  }
  return d
}

function getBreadcrumb() {
  // only show routes with meta.title
  let matched = route.matched.filter(item => item.meta && item.meta.title);
  const first = matched[0]
  // 判断是否为首页
  if (!isDashboard(first)) {
    matched = [{ path: '/index', meta: { title: '首页' } }].concat(matched)
  }

  levelList.value = matched.filter(item => item.meta && item.meta.title && item.meta.breadcrumb !== false)
}
function isDashboard(route) {
  const name = route && route.name
  if (!name) {
    return false
  }
  return name.trim() === 'Index'
}
function handleLink(item) {
  const { redirect, path } = item
  if (redirect) {
    router.push(redirect)
    return
  }
  router.push(path)
}

watchEffect(() => {
  // if you go to the redirect page, do not update the breadcrumbs
  if (route.path.startsWith('/redirect/')) {
    return
  }
  getBreadcrumb()
})
getBreadcrumb();
</script>

<style lang='scss' scoped>
.app-breadcrumb.el-breadcrumb {
  font-size: 14px;
  line-height: 50px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>